A true GTO play adjusts based on input, and is designed in such a way that you really don't care what your opponent does. You design your range and bet sizes in such a manner that every decision made by the opponent is equal in value to you. A fold is as profitable as a call, for example.
If your opponent deviates from their own GTO play, it can only profit the other player. So, if the GTO play for your opponent involves bluffing 30% of the time and, instead, they bluff 80% of the time then your opponent will be losing money from those extra bluffs. Obviously, if a GTO player were to recognize their opponent was deviating from the right play, the GTO player could make even more money from exploiting the mistake. But, even if they choose not to exploit that deviance, they will make more money from the deviation than if the opponent had played correctly.
When facing a raise, the GTO player will have a range of hands that reraises, a range that calls, and a range that folds (with some variation based on sizing). If the other player is bluffing too much, they win some extra from the folding range but lose even more to the calling and raising ranges. And the ranges are balanced so that the opponent can't just exploit them from a simple change like bluffing more.
Furthermore, GTO understanding is extremely helpful for recognizing when an opponent is making mistakes. If you know an opponent should defend 73% of the time in a specific spot but they only defend 60% of the time, you can then exploit that mistake. You won't be playing GTO at that moment, but your profit comes from understanding the theoretical correct move your opponent should make and recognizing that he isn't making it.
GTO is a framework for understanding what the correct move should be, to make it impossible for your opponent to make extra profit from one response compared to another. This is why I said your statement about bluffing ruining GTO makes it seem like you don't understand. You expect your opponent to bluff a certain amount, it is the right response. If they bluff less than that, you profit. If they bluff more than that, you profit.